#include <bits/stdc++.h>
using namespace std;

#ifndef ONLINE_JUDGE
    #include <bits/debug.h>
#endif

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T> using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += (int)(c))
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i <= (int)(b); i -= (int)(c))
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x) & (-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz(x) (int)(x).size()

void solve() {
    int n, m;
    cin >> n >> m;

    V<int> w(n);

    for (auto &x : w) cin >> x;
    set<int> s;
    int ans = 0;

    FORD(i, 0, n - 1) {
        V<int> vis(n + 1, 0);
        FOR(j, 0, i) {
            vis[w[j]]++;
        }

        bool f = false;
        FOR(j, 1, m) {
            if (!vis[j]) {
                f = 1;
                break;
            }
        }
        if (f) break;
        ans++;
    }
    cout << ans;
}

signed main() {
    int Task = 1;

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    while (Task--) {
        solve();
    }

    return 0;
}
